education & research archive

TransCanada Historical Research Reports

From the mid-1970s to the mid-1990s, Nova Gas Transmission Ltd., a subsidiary of TransCanada Pipelines Ltd. produced a series of research reports related to pipeline soil conservation practices. TransCanada realizes the importance of scientific research initiatives and is pleased to provide the numerous reports in digitized format to ensure the studies and respective findings are available to the general public.
TransCanada has agreed to allow the Alberta Centre for Reclamation and Restoration Ecology (ACRRE) to make these reports available through the University of Alberta Libraries Education & Research Archive (ERA).

Dissipation of Bromacil in Humic Luvic Gleysols in Northwestern Alberta

Creator:

Landsburg, S.

Description:

The dissipation of bromacil in Humic Luvic Gleysols amended with cow manure was evaluated at two sites in northwestern Alberta from 1984 to 1987. At each site, nine locations were sampled in 4 cm increments from 0 to 40 cm, and analyzed for bromacil, pH, electrical conductivity (EC), and organic carbon (OC). The addition of manure increased values for OC and pH within the surface 16 cm at Site 1 and 24 cm at Site 2. These increases reflected the inherent organic-alkaline nature of the manure itself. Largest increases for both variables occurred between 8 and 16 cm, indicating the predominant depth of cultivation and rooting.
Cow manure increased EC values within the surface 4 cm at Site 1 and 12 cm at Site 2. Decreases occurred between 24 and 40 cm at each site, and were caused by leaching. Cow manure promoted microbial degradation of bromacil through increased levels of OC. Bromacil concentrations were lower at the depths where OC percentages were higher. Bromacil concentrations were also reduced throughout the entire 40 cm at Site 2 by leaching. Leaching was restricted at Site 2 by an intermittent high water table, where bromacil concentrations were decreased only within the surface 12 cm. Overall, results of the study show bromacil to be dissipated by two methods: microbial degradation and leaching.

A study was initiated in 1988 to evaluate the effects of pipeline construction on soil compaction in the province of Alberta. The pipelines were located throughout Alberta on a number of different soils and were constructed using various techniques. Cone penetration resistance of soils (soil strength) was monitored to a depth of 31.5 cm at 14 study areas. Soil strength measurements were taken from right-of-way locations as well as from an adjacent undisturbed control. Soils were also analyzed to determine percent organic matter, moisture and clay.
Soil strength information from the 14 study areas suggests that pipeline construction procedures can cause changes in soil strength on pipeline rights-of-way in Alberta. However, decreases in soil strength on the RoW compared to adjacent controls are more common than increases. These differences in soil strength appear to be short lived in the majority of cases; most differences, both increases and decreases, had disappeared one year after construction or were less than 2 bars.
Although pipelines constructed through a number of different soils types were monitored, no clear relationships emerged between soil Orders, zones, or soil parent materials and the effect of pipeline construction on soil compaction. Soil moisture conditions appear to be more important. Pipelines constructed under moist to wet soil conditions were more likely to be compacted than if construction took place under dry soil conditions. Gleysolic soils for example were no more likely to be compacted during construction than soils of any other Order, provided construction took place under dry soil conditions.

Effect of Pipeline Construction on Soil Strengths of Soil Horizons in Alberta: 1990 Final report

Creator:

Cannon, K.R.

Description:

This study was initiated in 1988 to evaluate the effects of pipeline construction on soil strengths of various soils in the province of Alberta. The pipelines were scattered throughout Alberta on a number of different soils and were constructed using various techniques. At each of the fifteen 1989 study areas and at each of the eight 1988 study areas soil strength was monitored using a cone penetrometer in 15 cm depth increments to a depth of 52.5 cm. Soil strength measurements were taken from trench, work side and spoil side locations of the rights-of-way, as well as an adjacent undisturbed location.
Soil strength information from the twenty three study areas suggests that pipeline construction can cause changes in soil strength on pipeline rights-of-way in Alberta. Significant changes were observed in both topsoil and subsoil.

Impacts of Overstripping Topsoil on Native Rangelands in Southeastern Alberta: A Literature Review

Creator:

Landsburg, S.

Description:

This literate review evaluates the information available on the effects of overstripping topsoil during pipeline construction on native rangelands in southeastern Alberta. The effects on soil quality and handling of Chernozemic and Solonetzic soils are presented in detail as these are the dominant soils in southeastern Alberta.
The available information indicates that overstripping and subsequent replacement of topsoil can produce horizon characteristics similar to plow depth characteristics resulting from cultivation. In Chernozemic soils, overstripping may not greatly change quality of the soil replaced over the trench after pipeline construction because these soils have low salinity and sodicity levels, and only minor textural differences between A and B horizons. Overstripping may, however, decrease surface organic carbon content in Chernozemic soils. These minimal changes in soil quality suggest that Chernozemic soils could be overstripped without significant impact.
In most Solonetzic soils, overstripping topsoil can increase the clay content, soil strength in the Ap horizon, salinity, sodicity and pH in the soil replaced over the trench. It can also decrease water infiltration and organic carbon content, thereby increasing water erosion. Seedling emergence from the seedbed may be reduced by these changes. Some Solods may be overstripped without significantly changing topsoil quality, but this depends on the physical and chemical characteristics of the soil. The negative potential impacts of overstripping topsoil on many Solonetzic soils indicate that Solodized Solonetz and Solonetzic soils should not be overstripped.

Rangeland Revegetation Monitoring on Two Pipeline Rights-of-Way in Southern Alberta

Creator:

Naeth, M.A.

Description:

Field sites for this study were established in 1987 shortly after the completion of construction of two pipelines in southern Alberta. The Dry Mixed Grass and Mixed Grass Ecoregions (Milo Pipeline Lateral) and the Aspen Parkland, Montane and Fescue Grassland Ecoregions (Porcupine Hills Lateral) were selected for study plots to compare vegetative productivity, plant species composition and animal utilization on the pipeline right-of-way to that of the adjacent native grassland. Field assessments were conducted over four growing seasons.
Grass production decreased, as expected, in the first year after construction, but it then increased, and in the Dry Mixed Grass and Mixed Grass Ecoregions, often exceeded predisturbance levels. Grass production was higher on unseeded than seeded areas. Forb production showed an increase in the first year after the disturbance, and generally remained higher on disturbed treatments than on the control over time. Total herbaceous production showed a general increase with time on all disturbed treatments, particularly at the Milo sites, due to the increase in grass production.
Bare ground was not significantly different between the disturbed areas seeded to native species and the adjacent native grasslands, within four years of construction. For areas seeded to non-native species bare ground was still significantly higher in disturbed areas. After four years litter on areas seeded to native species was greater on the pipeline trench than in the adjacent control area. For all disturbed areas seeded with non-native species, litter was greater than for the controls.
A lack of little club moss on study sites in the Dry Mixed Grass and Mixed Grass Ecoregions resulted in less similarity between disturbed and undisturbed sites over time, especially in areas seeded to non-native species. In the Aspen Parkland, Montane and Fescue Grassland Ecoregions, plant species composition became more similar over time between the pipeline right-of-way and the adjacent control.
Grazing did not show a discernible effect on cover. There were strong, but highly variable trends for higher overall forage utilization on the pipeline trench than in undisturbed control areas at all sites.

The degree of soil compaction is dependent on many variables including soil type and soil conditions as well as vehicle type and traffic density. Soil compaction can lead to limited plant development because of poor aeration, low nutrient and water availability, slow water permeability and mechanical impedance to root growth. Documented studies concerned with pipeline construction have indicated that soil compaction can be a problem. Soil compaction is dealt with by acceptance, alleviation, avoidance and controlled traffic. The extent of soil compaction is often determined by measuring the change of a parameter as a consequence of a compacting effort.

The Long-Term Impact of Pipeline Construction on Solonetzic Mixed Prairie

Creator:

Naeth, M.A.

Description:

In 1981, a study was initiated near Princess, Alberta to evaluate single-lift pipeline construction impacts on Solonetzic mixed prairie rangeland. In August 1991, a further evaluation of the study sites was conducted to determine the longevity of the changes that took place on the 1981 right-of-way from using 1981 construction techniques. The study concentrated on the well-documented 1981 right-of-way, and compared it to the oldest trench, installed in 1957, and to the undisturbed adjacent mixed prairie.
It was still evident in August 1991, that single-lift pipeline construction in Solonetzic mixed prairie had significant effects on soil chemical, soil physical, hydrologic, and vegetative parameters of the ecosystem. Effects were similar to those documented in 1983. As in the first study, these effects and their changes over time were in turn affected by both the grazing regime imposed on the rangeland and the different construction activities at the time of pipeline installation, with trenching having the most significant impact. However, there was a distinct trend towards predisturbed conditions evident in many vegetation and soil chemical and physical parameters.
In August 1991, on the 1981 right-of-way vs the undisturbed prairie there was still increased surface bulk density and surface water; increased organic carbon, pH and sodium adsorption ratio to depths of 15 cm, and electrical conductivity to depths of 45 cm. Calcium, magnesium, sodium, sulphate, and chloride were decreased to 45 cm, and potassium below 5 cm. Soil bulk density with depth decreased in trench treatments and increased on work and stockpile treatments. In the trench, penetration resistance and depth to maximum penetration resistance decreased and soil water with depth increased. Bare ground, the number of introduced and pioneer (weedy) species, and cover of little club moss increased; species diversity and number of native species decreased.
A trend towards predisturbed conditions was evident on the rights-of-way from 1983 to 1991, although the magnitude of change was often small and not always statistically significant. The trend was characterized by decreased bare ground, increased species diversity and native species, and decreased native pioneer species. Downward salt movement in the 1981 trench and 1981 stockpile treatments was evidenced by decreases in electrical conductivity, sodium, sulphate, and sodium adsorption ratio to 15 cm and increases in these parameters below 15 cm. Soil bulk density at the surface and with depth decreased; there was a slight increase in organic carbon.
Grazing regime continued to impact the revegetated pipeline rights-of-way by increasing Elymus angustus under early season grazing and increasing Agropyron pectiniforme under late season grazing.

The objective of this study was to evaluate several pipeline topsoil stripping depths to determine whether they result in land capability equivalent to that of adjacent forested lands broken for cultivation. Topsoil stripping depths were 0 cm, 15 cm and 30 cm. Soils chosen for the study were Orthic and Gleyed Gray Luvisols located south and west of Beaverlodge in northwestern Alberta. The study site was covered with a mature aspen/poplar forest prior to construction. Percent soil organic matter, pH, electrical conductivity, and sodium adsorption ratio, soil strength and particle size distribution on the pipeline trench were compared with pre-disturbance soils and with adjacent controls (which were cleared of forest and subsequently broken for agriculture using breaking practices typical for this area) . Forage biomass, percent cover and species composition comparisons between controls and the trench were made.
Five years after construction, no differences between the trench and control areas in any of the vegetation parameters were found on any of the three stripping treatments. Any differences in soil quality were found not to affect vegetation productivity. Control data tended to be more variable than data for the trench. Topsoil from all three stripping treatments was rated 'good' in terms of organic matter 5 years after construction. No stripping (0 cm) of topsoil resulted in lower soil quality compared to the control in some instances, but the agricultural capability ratings for all treatments and their controls were equivalent.

The objective of this literature review was to evaluate the available information on the effects of stripping versus not stripping topsoil during pipeline construction in potentially arable Luvisolic soils in forested areas. A profile description representative of an undisturbed Luvisol under native forest vegetation was studied to identify potential problems in terms of soil quality and soil handling associated with the soil.
A review of the literature indicates there is little information on topsoil handling techniques during pipeline construction for forested areas considered arable. However, a review of related literature suggests that topsoil stripping of forested soils and its subsequent replacement would result in horizon characteristics similar to those of the plough depth resulting from farming practices. Removal and subsequent replacement of the subsoil is expected to result in a decrease in bulk density. This should improve hydraulic conductivity and aeration thereby allowing deeper root penetration for better moisture and nutrient extraction from the soil. Subsoil replacement is not expected to result in dramatic changes in particle size distribution , exchangeable cation concentration , total nitrogen or total organic carbon . An increase in pH could occur if calcium carbonate is brought up from the Ck horizon .
With no topsoil salvage , an increase in surface bulk density, pH and clay content is anticipated. Mixing of topsoil and subsoil would most likely result in altered physical properties similar to those previously discussed for removal and subsequent replacement of subsoil. Incorporation of organic matter from leaf litter and silt from the Ae horizon is not expected to change subsoil characteristics dramatically.
Although the discussion of potential impacts of pipeline construction on Luvisolic soils suggests that topsoil conservation may not be necessary, there are in sufficient relevant data in the available literature to clearly substantiate this conclusion. Further investigations are needed to ascertain the effect of stripping versus not stripping topsoil in forested areas considered arable.

Companies installing pipelines seek economical, practical and environmentally responsible methods of soil handling during pipeline construction to ensure successful soil reclamation.
The objectives of the Twelve Mile Coulee Soil Research Project are to evaluate the impact of pipeline construction on Solonetzic soil quality and salt movement in the Brown soil zone. This research addresses soil handling practices on actively grazed native prairie in a landscape dominated by Brown Solonetz soils developed on till. Topsoil overstripping with a stepblade versus no stripping of trenchline (for small lines) is compared. Several important findings two years after summer construction are:
• A step blade is effective in overstripping topsoils to re-establish fair surface soil quality as compared to poor quality on no strip plots. The native soils have a 10 cm Ah over an Ae and Bnt horizon sequence. Overstripping to 20-25 cm salvages the Ah to upper B horizons. Upon reclamation, the capability of overstripped soils is slightly better (about half a class) than that of no stripped soils.
• There is increased topsoil salinity in both overstripped and no stripped treatments, but higher salinity in the latter. In overstripped treatments topsoil salinization occurs during topsoil replacement rather than during stripping.
• In this prairie landscape dominated by Brown Solonetz soils, vegetation is responding well on both the overstripped and no stripped treatments.
• No topsoil stripping is a viable alternative on straight lines, but is not viable on road and pipeline crossings or other major disturbances.